Unforunately, I don't think they will. They aren't really equipped to have any older children in there. Also, I think your 8 yo would be incredibly bored. Flounders isn't that big, and they limit the number of children they allow in, unlike the clubs where all children above 3 are allowed. I didn't think my them 18 month old velcro would like it, but he LOVED IT!!!! We brought him there and during sign up, let him play and get used to the place for at least half an hour. It helped him, and when we dropped him off, off he went to explore all the new toys. We checked back on him frequently that first night, and he was completely fine!!! The counselors are GREAT, so I wouldn't worry!!
